No quick or easy technological fix for climate change:

Global warming, some have argued, can be reversed with a large-scale “geoengineering” fix, such as having a giant blimp spray liquefied sulfur dioxide in the stratosphere or building tens of millions of chemical filter systems in the atmosphere to filter out carbon dioxide.

But Richard Turco, a professor in the UCLA Department of Atmospheric and Oceanic Sciences and a member and founding director of UCLA’s Institute of the Environment, sees no evidence that such technological alterations of the climate system would be as quick or easy as their proponents claim and says many of them wouldn’t work at all.

Turco will present his new research on geoengineering — conducted with colleague Fangqun Yu, a research professor at the State University of New York–Albany’s atmospheric sciences research center — today and Thursday at the American Geophysical Union’s annual meeting in San Francisco.

“We’re talking about tinkering with the climate system that affects everybody on Earth,” said Turco, an atmospheric chemist with expertise in the microphysics of fine particles suspended in the atmosphere. “Some of the ideas are extreme. There would certainly be winners and losers, but no one would know who until it’s too late.

“If people are going to pursue geoengineering, they have to realize that it won’t be quick, cheap or easy; indeed, suggestions that it might be are utter nonsense, and possibly irresponsible. Many of these ideas would require massive infrastructure and manpower commitments. For example, one concept to deliver reflective particles to the upper atmosphere on aircraft would require numerous airports, fleets of planes and a weather forecasting network dedicated only to this project. Its operation might be comparable to the world’s entire commercial flight industry. And even after that massive investment, the climatic response would be highly uncertain.”

Given the difficulties of reducing greenhouse gas emissions, the idea of a simple large-scale technological solution to climate change can seem very appealing.

“Global warming due to carbon dioxide emissions appears to be happening even faster than we expected,” Turco said. “Carbon dioxide emissions are continuing to grow despite all of the warnings about climate change, despite all of the data showing such change is occurring and despite all of the efforts to control carbon emissions. The emissions are rising, in part, because China and India are using increasingly more energy and because fossil fuels still represent the cheapest source of energy.

“If we continue down this path, the climate is likely to change dramatically — major ice sheets could melt, sea levels could rise, it may evolve into a climate catastrophe. So it is tempting to seek an alternative response to climate change in case we can’t get emissions under control. The result is that more and more geoengineering proposals are surfacing. Some of the people developing such proposals know what they’re talking about; many don’t.”

Turco and Yu have been studying a particular geoengineering approach that involves the injection of nanoparticles, or their precursor gases — such as sulfur dioxide or hydrogen sulfide — into the stratosphere from aircraft or large balloons.

See the article for more detail, especially on the nanoparticle idea.

Once again, I think it’s all but inescapable that we’ll wind up resorting to one or more geoengineering schemes in the next few decades. Not because they’re “good” ideas in any meaningful way, except that they’ll be the only tools left in our toolbox. We’ll continue to make no more than token progress on the CO2 emissions issue, taking several baby steps when a running broad jump is needed. Eventually real-world events (pick your own set of horrors) will make us hit a psychological tipping point, when even the most well funded and ardent deniers and delayers won’t be able to stop large scale action–but all that will be left will be seeding the atmosphere or ocean, or deploying clouds of orbital or sea-surface mirrors, or who knows what.